Vibration damper



Ma rch 17, 1953 M. M. HOLBEN ETAL VIBRATION DAMPER 2 SHEET -SHEET 1 Filed Dec. 1, 1949 TORS HDLBEN. JEWETT.

INVEN MARTIN M. BYEHARLES 5.

M 4. awn.

ATTORNEY March 17, 1953 M. M. HOLBEN ETAL VIBRATION DAMPER 2 SHEETSSHEET 2 Filed Dec. 1, 1949 lNVENToRs MARTIN M. HUI-BEN. EHARLEE: 5. wr:TT.

Zn A511 ATT DRflEY Patented Mar. 17, 1953 Jewett; Hasbrouck Heights, N. J assignors to Gui-tiss- -Wright:.Corporation, a corporation of Delaware:

np icaticn Decem ien, SeriaINo..1 30 4f18 iz Claims.

This invention relates to vibration dampingmeans and is particularly directedto means for damping lateral-vibrationsof a rotating member.

Any unbalance in a high Speed rotating shaft such as the shaft of-a gastur-bine; causes-severe lateral vibrationof said shaft; An objectof the present invention comprises-the provision of -anovel viscous damper -fordamping said lateral vibrations.

In accordance with the present invention the shaft whose lateral vibrations are to be damped is supported in-a bearing and the non-rotating outer race of-said bearing is received withinan'annular channel in the bearingesupporting member. In addition, flexible sleeve-like means isdisposed between-said non-rotating-bearingrace and thebottom of saidchannel.-

tom of said'channel has. a plurality of circum ferentiall-y spaced ribs and'atleast one of the. facing surfacesof said sleeve likemeans and said non-rotating bearing :race has a pluralityof circumferentially spaced :ribs, said'ptwosets of ribs being circumferentiallyv sta gered relative-to each Each of said sets of ribs formsfaepluralityw of cir-cumferentiallylspaced spaces around its. as-- other.

sociated. surface of said. sleeve-dikemea-ns to which a suitableliquid; asplubricating oil, is 'sup,-.

plied. Lubricating oil is supplied to. said spaces through a. plurality of circumferentially spaced 1 passageways openingthrough thebottom surface; of said channel.- Each of said; passageways; is adapted to beclosed by saidsleeve-likemeans. when said sleeve-like. means-ispressed against-- the, bottom surface of saidchannel aboutsaid passageway. With thisconstruction lateralyibrations of said shaft cause. de lections of said;

sleeve-like means to, varythe; relative volumes of said inter-rib; spaces; thereby-causing oil to flow between said spacestodamp saidshaftvibrations. In additionoil;issqueezed between said non-rotatinsbtearins. acean the s e wall offsaid channel to further darnp; saidwibration s.

Oth r. obi eatsv of 2. 118 inre ti niwillbec m rr pa nt up n r amin :th ;anne ed; etai e de.. c iption in, conne t qm w th. th y drawi n:

which 2 Figure 1 is; an axial sectional ;view; througha,

shaft and ashaft support embodyingthe invention and taken al n 1 .13.1 i' fi -l f zi Figure Zisa sectionalviewtaken along line'2-e2,

of Figure 1;

Figure. 3 is. a .viewltaken .alon iine rB of Fig-,-

ure 2; and

. Figure-w t: isian @enlarged viemiot aportion of Figure 1.

Atleast one of the-facingsurfaces of said'sleeve-likemeans and the bot Referring to the drawing, a shaft I is jour;-'

naled in a roller bearing l2 having an inner race M -secured-to and above the shaft I0 and having an outer race I6. The outer race It is secured to an-annular member l8 which is held invposition about the outer'bearing race by a split ring 20.

As will appear, however, the annular member l8" may be formed rigid withthe outer bearing" race I6.

The-annular bearing-member I8 is received;

within an annular inwardly opening channel 22 formed-in and carried'by the supporting structure 2-5,- said member I8- having limited radial freedom relative to the support 24. This channel 22 is formed b-ya plate 26 which is-secured' to the support 24 by screws 28-. The internal dimensions of the channel 22 are accurately determined by rings 3!} and 32 secured-therein. The

ring 33 has a right angle cross-section with oneleg 34 having a shrink fit with the support 24. The other leg 35 of the ring 30 and the ring 32- form the: side wallsof the channel 22, said side wallsbeing held apart by spacing bushings-38 disposed about the screws28, The spacing bushings 38 extend through the annular bearing member- I8 in clearance relation thereto, as indicated at ifi, to permit radial or lateralmovementof saidbearing relative to its supporting struc-,.

ture 24.

A. sleeve 42 is disposed between the annular: bearing-member l8 and the bottom of the chan-.

nel .22, said sleeve preferably being -split,- as illusitrated, into a plurality of segments disposed in end-to-end relation to form a complete ring. On; the. outer surfaceof thesleeve 42 is formed a plu.--. ralityof circumferentially spaced ribs 44 extend-. ing. axially from one end face of said-ring to its other end face with a rib disposed at each end.

The outer surface of theof said ring segment. annular bearing member 18 is also provided with a plurality of circumferentially spaced ribs 46 extending axially from one end of said member to its other end.. The ribs 45 are circumferentially staggered relative'tothe-ribs 44. This stagg red relationship is maintained by means of a.plu-- rality of pairs of pinsa secured to the bearing member; !8 which isheld against rotation by the screws 128.: segments of the sleeve 42 have the heads of a pair of said pins disposed therebetween, as. best seenin Figure 3, thereby preventing rotation of said sleeve. The sleeve 42 is flexible and in the normal or -non defiected position of the shaft Ill, all the ribs M1;- contact the; bottom surface of the channel 22ers! alls heribs 1 s ntact heflexible- V sleeve 42 whereby said sleeve and bearing 12 pro- Each pair of adjacent ends of the 3 vide a resilient support for the shaft l permitting limited lateral or radial movement of said shaft. Thus any unbalance force on the shaft I0 is transmitted to the flexible sleeve 42 through one or more of the ribs 46 on the side of the shaft toward which said force is directed. Then because the adjacent ribs 44 are in contact with the bottom of the channel 22, the flexible sleeve 42 will bend between said ribs 44 and 4B. The multi-segment construction of the sleeve 42 increases its flexibility to lateral deflections of the shaft ID as compared to a one-piece construction.-

A suitable liquid, as for example lubricating oil, is supplied to the channel 22 from a pump 50 through a supply passageway 52 to an annulus formed about the leg 34 of the ring 30 and then through a plurality of circumferentially spaced passageways 55 communicating with said annulus. The passageways 55 comprise holes through the leg 34 of the ring 383 whereby lubricating oil is supplied through and at a plurality of circumferentially spaced points along the bottom surface of the channel 22. As a result the spaces between the ribs 44 and the spaces between the ribs 5%; become filled with oil. Each of the inter-rib spaces is in restricted communication with the other inter-z'ib spaces around the axial end faces of the sleeve 42. In addition, the clearance 58 between the annular bearing member l8 and the side walls of the channel 221s small, thereby providing a restricted lea age flow path for lubricating oil from the bottom of the channel 22. For example, the clearance 58 may approximate 0.001 inch which as illustrated is considerably less than the clearance between the flexible sleeve 42 and the side walls of the channel 22.

Each of the passageways 55 opens into the channel 22 over one of the ribs is and said ribs have an outer cylindrical surface similar to the cylinder bottom surface of the channel 22 about said passageways so that each of said passageways is closed when its associated rib is pressed against the surrounding bottom surface of the channel 22.

With the aforedescribed construction, when the shaft ii deflects laterally from its normal position the sleeve 52 will bend or deflect between one or more ribs as and/or between one or more ribs 46, thereby changing the relative volumes of the inter-rib spaces. Thus the volume of one or more inter-rib spaces on the side of the shaft l8 toward which said shaft has deflected is reduced as a result of said deflection, whereby oil is squeezed or displaced out of said inter-rib space. Most of this displaced oil is forced into other inter-rib spaces whose volume is increased as a result of said shaft deflection. some of said displaced oil is forced out through the restricted passageway or clearance 58 between the annular member 48 and the side walls of the channel 22. When the shaft it deflects laterally the ribs 44, on the side of said shaft toward which said shaft deflects, press against the bottom surface of the channel around "the adjacent inlet passageways 5% thereby closing said passageways to at least substantially prevent the oil squeezed out of the spaces between the ribs is from being pumped or forced back into the supply passageway 52.

As the unbalance force on the shaft H3 and its resulting shaft deflection advance around the axis of said shaft, the volumes of one or more inter-rib spaces, on the side of the shaft toward which said shaft is momentarily deflected, are

4 reduced relative to other inter-rib spaces. Accordingly, as the shaft H3 rotates oil is transferred around the shaft between said inter-rib spaces via the clearance between the end faces of the sleeve 42 and the side walls of the channel 22. This oil transfer together with that forced through the clearance 58 absorbs energy, thereby damping vibrations of the shaft 10.

In addition to the oil forced through the clearance 58 because of vibrations of the shaft 10, there is a continuous leakage flow through this clearance. The oil lost through clearance 58 is continually replaced through the oil supply passageway 52 and the open passageways 58. At any one moment the open passageways 56 are on the side of the shaft I0 remote from the side toward which said shaft has deflected. This continual oil flow from the inter-rib spaces through the clearance 58 helps to carry away the heat produced by the viscous damping of the shaft vibrations as a result of the aforedescribed oil flow.

While we have described our invention in detail in its present preferred embodiment, it will be" obvious to those skilled in the art, after understanding our invention, that various changes and modifications maybe made therein without departing from the spirit or scope thereof. We aim in the appended claims to cover all such modifications.

, We claim as our invention:

1. Means for damping lateral vibrations of a rotating shaft; said means comprising a support for said shaft; a bearing carried by said support and within which said shaft is journaled, said bearing having an annular bearing portion received within an annular inwardly opening channel said support for limited radial movement relative to said support; sleeve-like means disposed about said annular bearing portion between said portion and the bottom of said channel; a first plurality of .circumferentially-spaced axially-extending ribs disposed between the bottom surface of said channel and the outer surface of said sleeve-like means and being rigid with one of said surfaces for engagement with.

the other of said surfaces; a second plurality of circu'mferentially-spaced axially-extending ribs disposed between the inner surface of said sleeve-like means and the outer peripheral surface of said bearing portion and being rigid with one of said surfaces for engagement with the other of said surfaces, said first plurality of ribs being circumferentially staggered relative to said second plurality ribs and the space between each adjacent pair of ribs being in communication with other inter-rib spaces through the space between said sleeve-like means and a side wall of said channel; a plurality of circumferentially-spaced passageways for supplying liquid into said channel to the inter-ribspaces, s'aid sleeve-like means being flexible whereupon lateral vibrations of said shaft cause said sleevelike means to flex'to vary the'relative volumes of said inter-rib spaces and cause flow of said liquid relative to said inter-rib spaces thereby damping said vibrations, each of said passageways opening into said channel through its bottom surface at a'point spaced from the side walls of said channel and at one of the ribs of said first'plurality' such that the channel end of said passageway is adapted to be closed by flexing of said sleeve-like means upon deflection of said shaft toward said rib.

2. Means for damping lateralyibr'ations of a rotating shaft; said means comprising a support for said shaft; a bearing carried by said support and within which said shaft is journaled, said bearing having an annular non-rotating portion received within an annular inwardly opening channel in said support for limited radial movement relative to said support; cylindrical sleevelike means disposed about said non-rotating bearing portion between said portion and the bottom of said channel, said sleeve-like means comprising a plurality of segments disposed in end-toend relation to form a complete annulus; means for preventing rotation of said sleeve-like means relative to said support; a first set of circumferentially spaced ribs formed on and extending axially along the outer surface of said sleeve-like means and engageable with the bottom surface of said channel; a second set of circumferentiallyspaced axially extending ribs formed on one of the inner surfaces of said sleeve-like means and the outer peripheral surface of said non-rotating bearing portion so as to be engageable by the other of said surfaces, said first and second sets of ribs being circumferentially staggered relative to each other and the space between each adjacent pair of ribs being in communication with other inter-rib spaces through the space between said sleeve-like means and the side walls of said channel; a plurality of circumferentially spaced passageways in said support for supplying liquid into said channel to the inter-rib spaces, said sleeve-like means being flexible whereupon lateral vibrations of said shaft cause said sleevelike means to flex to vary the relative volumes of said inter-rib spaces and cause flow of said liquid relative to said inter-rib spaces thereby damping said vibrations, each of said passageways opening into said channel through its bottom surface at a point spaced from the side walls of said channel and over one of the ribs of said first set such that the channel end of said passageway is adapted to be closed by said rib as a result of flexing of said sleeve-like means upon deflection of said shaft toward said rib.

3. Means for damping lateral vibrations of a rotating shaft; said means comprising a support for said shaft; a bearing carried by said support and within which said shaft is journaled, said.

bearing having an annular bearing portion received within an annular inwardly opening channel in said support; sleeve-like means disposed about said annular bearing portion between said portion and the bottom of said channel; a first set of circumferentially-spaced ribs extending axially along one side of said sleeve-like means and adapted to transmit forces from said shaft to said sleeve-like means; a second set of circumferentially-spaced ribs extending axially along the other side of said sleeve-like means and adapted to transmit said forces from said sleevelike means to the bottom of said channel, said first set of ribs being circumferentially-staggered relative to said second set of ribs and each interrib space being in communication with other inter-rib spaces through the space between said sleeve-like means and an adjacent side wall of said channel; and a plurality of circumferentially-spaced passageways for supplying liquid into said channel to the inter-rib spaces, said sleeve-like means being flexible whereupon lateral vibrations of said shaft cause said sleeve-like means to flex to vary the relative volumes of said inter-rib spaces and cause flow of said liquid relative to said inter-rib spaces thereby damping said vibrations, each of said passageways opening into said channel through its bottom surface at a point spaced from the side walls of said channel and at one of the ribs of said second set such that the channel end of said passageway is adapted to be closed by flexing of said sleeve-like means upon deflection of said shaft toward said rib.

4. Means for damping lateral vibrations of a rotating shaft as recited in claim 3 and including means providing a drain passageway coinmunicating with said inter-rib spaces and having a flow resistance relatively large compared to that of the flow paths between the inter-rib spaces.

MARTIN M. HOLBEN. CHARLES S. JEWETT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 421,089 Wood Feb. 11, 1890 1,593,251 Flintermann July 20, 1926 2,403,489 Birmann July 9, 1946 2,515,861 Campbell July 18, 1950 

